ERIE Tilt Mixer

Construction

The ERIE mixer drum shell is made of 3/4" steel in the cylinder section. During manufacture, the drum-around tolerance is held to a tight specification of ±.031”. This drum-around tolerance ensures a tight fit between the drum shell and bull gear.

The bull gear is made of a single-piece, 1045 carbon steel forged ring holding to the same tight specs (±.031”) found in the drum section. The gear provides both the gear teeth that the pinion gears will drive as well as the track that the main rollers will ride on. The gear teeth are machine cut into the forged ring. ERIE firmly believes that this process is superior to flame cut teeth in general use today and accounts for the near perfect mesh achieved between the pinions and bull gear on the ERIE mixer. The weld between the bull gear and drum shell are then checked with ultrasonics by an independent testing company ensuring that there are no defects.

The ERIE mixer drum is supported by two main rollers. Each roller assembly is made of 4140 alloy steel, annealed for wear hardening and machined to a close tolerance of ±.002”. Each roller mounts on a steel shaft with heavy duty Timken bearings.

The ERIE mixer is held in vertical alignment by three sets of edge rollers. Each edge roller is made of 4140 steel, annealed for wear hardening and machined to a close tolerance of ±.002”. The roller assemblies are mounted on steel pads with slotted adjustment holes to provide the exact vertical positioning of the drum.

The unique hinge and link tilting mechanism on the ERIE mixer is like no other in the industry. This design allows the mixer to discharge farther out in the drive-lane, higher than others with a 55 degree tilt angle. This keeps the rest of the plant lower and helps to keep the mixer cleaned out better.

Ball bushing design in the hinge, link and cylinders allow for the mixer during discharge to accommodate the shifting loads and float on special ball bushings rather than on rigid pin connections which could cause failure and fatigue.

Hydraulics

Load sensing, variable displacement piston hydraulic pump, will only output the amount and pressure of oil needed for the selected speed of tilting

Infinite variable speed control of the mixer’s tilt action allows the operator to dial-in tilt speed to meet loading demands for different trucks or mix designs.

A 160 gallon hydraulic oil tank capacity and optional water cooled heat exchanger ensure low operating temperature in the harshest environments. Hydraulic pump is located under the tank which provides a constant flooded condition that ensures the pump to never lose hydraulic prime.

Counterbalance valves at the bottom of the tilt cylinders provide anti-drop protection in the event of a hose or fitting failure.

Mixing / Drum Rotation

Two 75HP Lincoln Electric TEFC motors drive the Auburn Gear reducers through a flexible coupling which greatly reduces the shock loads from being transferred back to the motor. The motor bed plates are adjustable, allowing the backlash to be easily adjusted.

At the heart of the ERIE mixer are four contoured buckets and four contoured two-section blades uniquely manufactured and positioned in the drum to provide the most thorough mixing action of the concrete found in a drum mixer today. As the water, aggregate and cement are charged into the drum, the four blades work to pull the materials forward. The four buckets then act to plow the materials back. As the drum turns, the aggregates, water, and cement are continuously folded back into each other to provide a complete uniform coating of the cement paste to the aggregates. This mixing action is, in fact, so complete that the ERIE mixer has been approved for mix times of as little as 30 seconds.

Dust Control w/ ERIE Optional Nose Plug

The ERIE mixer utilizes a nose plug to minimize the amount of cement lost to the dust collector by capping off the front of the mixer during charging & mixing. Other tilt mixer suppliers collect the dust at the discharge end of the mixer. This method results in more dust (cement) being collected that would otherwise remain in the mixer drum. In addition, the collection device on the mixer discharge is much more susceptible to concrete buildup. In operation, the dust plug is in place capping the front of the mixer (discharge end) while the materials are being charged into the back (charging end). The dust created is directed towards the front of the mixer which is capped thereby forcing the dust to migrate back to the charging opening where it is collected. In this process, more dust is captured in the mix as it moves from back to front and back again.